1. Field
This invention pertains to ski boots of the type in which an inner boot is removably placed within a rigid outer shell. Specifically, it provides both an improved pliable inner boot and an injectable fit pack adapted for custom fitting inner boots of this type to individuals of varying foot characteristics.
2. State of the Art
Over the past several years, ski boots have evolved through several stages from stiff unlined boots of leather to the present rigid outer boot shells (generally of plastic) with flexible liners of various types. For use with modern bindings, it is essential that the outer boot be stiff to optimize the control effected on the skis by a skier shifting his weight or the attitude of his feet. On the other hand, the inner boot desirably provides for adequate comfort so that the skier can tolerate wearing the boots for extended periods.
Inner boots have been sold with ski boots for many years. More recently, some of these inner boots have been constructed of microcellular foam material. Some of the prior art inner boots have included bladders adapted to receive injections of moldable materials. Although various injection techniques have been used to custom fit inner boots to individual feet, the industry would prefer to avoid such techniques. Injection techniques are capable of producing an excellent fit, but care and experience beyond the level typically available at the retail level are required for consistently satisfactory results.
To avoid the problems experienced at the retail level from custom fitting methods involving the injection of elastomeric material to custom fit the inner boot to an individual's foot, various types of so-called "flow" systems have been tried. Although a satisfactory fit is usually obtained initially by these methods, the fit is usually of temporary duration. Moreover, flow systems tend to reflow upon storage of the boots necessitating refitting after prolonged storage or transport under varying heat conditions. Accordingly, a large segment of the industry has moved towards systems which rely upon other expedients, such as insertable pads or wedges, to adapt a ski boot to an individual's foot. These methods are laborious. Although they can accomplish a reasonably good fit, they cannot achieve an ideal custom fit as was generally the case with injectable systems.
Custom fitting systems of the prior art are disclosed by U.S. Pat. Nos. 3,377,721; 3,410,004; 3,581,412; and 4,068,337. Typical flow fit systems are disclosed by U.S. Pat. Nos. 3,237,319; 3,786,580; and 3,402,411. Some of these patents also disclose inner boots of microcellular foam.